1. Field of the Invention
This invention relates to an improvement for a plotter system for temporarily storing image data in an intermediate memory and then transmitting it to an image forming portion.
2. Description of the Prior Art
As a system of this type, there have been used apparatus, such as, for example, a laser photo plotter. Such an apparatus comprises a raster engine for converting image data to raster data, and a plot portion for drawing a pattern on an image drawing surface, based on the converted data.
Because the conventional plotter system directly inputs the data from the raster engine to the plot portion, it is required that the raster engine and the plot portion be operated in synchronism. When the raster engine and the plot portion are operated in synchronism, the processing speed of the whole system is restricted by either the raster engine or the plot portion, which has a lower capacity.
In a general plotter system, drawing the capacity of the plot portion is higher than the data conversion capacity of the raster engine, and the processing speed of the whole plotter system is decided by the capacity of the raster engine.
The activation of the plot portion is sometimes stopped, for example when the drawing portion is switched. In such a case, the conventional system stops the activation of the raster engine.
However, it is not desirable to stop the activation of the raster engine, which has a low processing capacity, in view enhancement of the processing speed of the system.